Human bodies, as well as other organisms and substances, produce electromagnetic radiation in the form of, for example, heat or infrared radiation. In certain circumstances it may be desirable to retain this radiation, such as, for example, applications in which maintaining body heat or food temperature is desired. For example, once a food product is cooked, it may reach a certain temperature; however, this heat is often lost by exposure to cooler temperatures such as ambient air. In another example, a human body may be exposed to cooler temperatures, and infrared radiation may be lost through the epidermis. Retaining this infrared radiation, may have certain beneficial properties including maintaining a particular temperature, evading detection by infrared sensors, insulating pipes and other construction materials to prevent heat transfer, and providing heat to prevent joint stiffness. Known fibers do not completely solve the escape of radiation from a heat-emitting object, without also creating moisture or other undesirable side effects.